//鼠标移过来的动作。显示当前图片，清除轮询。 
function adchangea(adid) { 
dochange(adid); 
clearTimeout(adisround); 
} 
//自动轮询 
function adchangea2(adid) { 
dochange(adid); 
var adbigimg = document.getElementById("adpica").getElementsByTagName("div"); 
if ((adnext = adid + 1) > adbigimg.length) adnext = 1; 
adisround = setTimeout('adchangea2(' + adnext + ')', 3000); 
} 
//显示当前图片 
function dochange(adid) { 
id = adid; 
var adbigimg = document.getElementById("adpica").getElementsByTagName("div"); 
var adsmallimg = document.getElementById("adtipa").getElementsByTagName("li"); 
for (var adi = 0; adi < adbigimg.length; adi++) { 
adbigimg[adi].className = "hidden"; 
adsmallimg[adi].className = ""; 
} 
adbigimg[adid - 1].className = "show"; 
adsmallimg[adid - 1].className = "current"; 
} 
var adisround = setTimeout("adchangea2(1)", 1000); 
var id;//当前激活id 
//鼠标移开ul块时，恢复轮询 
function change() { 
adchangea2(id); 
} 